This invention relates to metrological scales e.g. scales for use in opto-electronic scale-reading apparatus. Such scales are known to comprise an elongate metallic scale member having alternate marks and spaces provided at a longitudinal surface thereof. It is known to provide the marks by lithographic methods but such methods are not readily suitable for making the scale in substantial lengths or in continuous lengths. It is also known for the scale member to be a flexible tape and the known lithographic methods are not readily suitable for producing the scale in a continuous way, possibly for reels of such tape. It is an object of this invention to overcome or reduce at least some of those difficulties. The invention may be considered in three aspects, viz. a method, a blank scale and finished scale.